ALD metal oxide deposition process using direct oxidation

ABSTRACT

Methods of forming metal compounds such as metal oxides or metal nitrides by sequentially introducing and then reacting metal organic compounds with ozone one or with oxygen radicals or nitrogen radicals formed in a remote plasma chamber. The metal compounds have surprisingly and significantly improved uniformity when deposited by atomic layer deposition with cycle times of at least 10 seconds. The metal compounds also do not contain detectable carbon when the metal organic compound is vaporized at process conditions in the absence of solvents or excess ligands.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of co-pending U.S. patentapplication Ser. No. 10/247,103, filed Sep. 19, 2002, which claimsbenefit to U.S. Provisional Application Ser. No. 60/388,929, filed Jun.14, 2002, both of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention relate to deposition methods forforming thin films of metal compounds, such as metal oxides or metalnitrides, on substrates for use in manufacturing semiconductor devices,flat-panel display devices, and other electronic devices.

2. Description of the Related Art

In the field of semiconductor processing, flat-panel display processingor other electronic device processing, chemical vapor deposition (CVD)has played an important role in forming films on substrates. As thegeometries of electronic devices continue to shrink and the density ofdevices continues to increase, the size and aspect ratio of the featuresare becoming more aggressive, e.g., feature sizes of 0.07 microns andaspect ratios of 10 or greater are contemplated. Accordingly, conformaldeposition of materials to form these devices is necessary.

While conventional CVD has proven successful for device geometries andaspect ratios up to 0.15 microns, the more aggressive device geometriesrequire new, innovative deposition techniques. Techniques that arereceiving considerable attention include rapid cycle (pulsed) CVD andatomic layer deposition (ALD). In such schemes, reactants are introducedsequentially into a processing chamber where each reactant adsorbs ontothe surface of the substrate where a surface reaction occurs. A purgestep is typically carried out between the delivery of each reactant gas.The purge step may be a continuous purge with the reactant gases or apulse purge between the delivery of the reactant gases.

Deposition of metal compounds from metal organic compounds typicallyresults in trace amounts of carbon in the deposited film. The carbon isintroduced into the film from the organic groups on the metal organiccompound or a solvent such as toluene that may be added to assist invaporizing the metal organic compound, or both. Although ALD enhancesmolecular reactions at the surface of the substrate between the metalorganic precursors and reactive gases, the process temperatures andreaction times used for ALD typically do not reduce the carbon contentbelow detectable limits. The residual carbon typically is an impuritythat may migrate to surrounding layers.

U.S. Pat. No. 6,200,893, entitled “Radical-assisted Sequential CVD,”describes a method for CVD deposition on a substrate where radicalspecies such as hydrogen and oxygen or hydrogen and nitrogen areintroduced into a processing chamber in an alternating sequence with aprecursor. Each compound, the radical species and the precursor, areadsorbed onto the substrate surface. The result of this process istwo-fold; the components react with each other, as well as prepare thesubstrate surface with another layer of compound for the next step. Byrepeating the cycles, a film of desired thickness is produced. In apreferred embodiment the depositions from the molecular precursor aremetals, and the radicals in the alternate steps are used to removeligands left from the metal precursor reactions, as well as to oxidizeor nitridize the metal surface in subsequent layers. However, thereference does not address removal of carbon from metal compoundsproduced from metal organic compounds.

Therefore, there is a need for a process for depositing metal compoundssuch as metal oxides and metal nitrides from metal organic compounds toprovide thin films that do not have detectable carbon.

SUMMARY OF THE INVENTION

The present invention provides deposition processes in which metalorganic compounds comprising the structure (R′RN)_(n)M, where n=1-4, aresequentially deposited on a substrate surface and reacted with ozone ora reactive oxygen or nitrogen species formed in a remote plasma chamber.Atomic layer deposition is the preferred deposition process and isobtained by controlling processing conditions such as temperature andpulse cycles. The metal organic compounds preferably exist in a gaseousstate at process conditions and can be vaporized without addition ofsolvents.

An exemplary embodiment of the invention deposits surprisingly uniformfilms of hafnium oxide from compounds that include the structure(R′RN)₄Hf, wherein either or both of R and R′ is an alkyl group havingfrom one to four carbon atoms, and where R and R′ may be the same groupor may be different groups. A preferred compound istetrakis(diethylamido) hafnium (TDEAH). In a pulsed atomic layerdeposition process, the TDEAH is adsorbed on a substrate surface at atemperature of less than 220° C. and then reacted with ozone or oxygenradicals generated in a remote plasma chamber. A pulse time of about 12seconds or less significantly and surprisingly provides uniform hafniumoxide film deposition which can be used to form conventionalsemiconductor films such as high k gate dielectric layers or high kcapacitor dielectric layers.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a generic structure for tetrakis(dialkylamido) hafniumcompounds which are preferred metal organic precursors for the first andsecond embodiments of the present invention;

FIG. 2 is tetrakis(diethylamido) hafnium (TDEAH), a compound used in theexamples of the present invention;

FIG. 3 is a cross sectional view of one processing chamber which can beused to advantage to deposit a metal compound according to embodimentsof the invention;

FIG. 4 shows the surprising uniformity of hafnium oxide films depositedby the present invention using TDEAH and further shows the substratetemperatures that produce uniform hafnium oxide films;

FIG. 5 shows the effect of pulse time on uniformity of the hafnium oxidefilm of the present invention;

FIG. 6 shows that carbon is not detectable in the hafnium oxide filmusing the ALD method of the present invention; and

FIG. 7 (comparison) shows that carbon is detectable in a hafnium oxidefilm produced from the precursor of FIG. 2 using MOCVD.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments of the present invention relate to an atomic layerdeposition or a rapid chemical vapor deposition process for forming athin layer of a metal compound on a substrate. A metal organic precursorcomprising the structure (R′RN)_(n)M where n=1-4, and where at least oneof R and R′ is an organic group, is introduced into a processingchamber, adsorbed on a substrate surface, then reacted with ozone orwith another reactive oxygen species formed in a remote plasma chamber.

The deposited metal compounds do not contain detectable amounts ofcarbon. Removal of detectable carbon is aided by the absence of solventsand excess ligands in the metal organic precursors. The preferred metalorganic precursors are hafnium compounds having the structure shown inFIG. 1 wherein both R and R′ are an alkyl group having from one to fourcarbon atoms. Most preferably, R and R′ are the same alkyl group. Themost preferred metal organic compounds include tetrakis(diethylamido)hafnium (TDEAH), which is shown in FIG. 2 and is commercially available.

In order to form a conformal film on a substrate from TDEAH by atomiclayer deposition, the substrate is heated to a temperature of betweenabout 150° C. and about 220° C. The TDEAH is pulsed into the chamberthrough the gas delivery system using a carrier gas, such as nitrogen orargon, at a pressure from 0.1 Torr to 10 Torr. The pulse of TDEAHrequires less than 12 seconds to deposit an adequate amount of TDEAH onthe substrate surface under the conditions described; however oneskilled in the art recognizes that the TDEAH pulse need only be longenough so that substantially a monolayer of TDEAH is deposited.Following the pulse of TDEAH, the carrier gas/TDEAH flow isdiscontinued, and a pulse of a purge gas, such as nitrogen, helium orargon, is introduced. The pulse of the purge gas may last for about 12seconds or less, and need only be long enough to clear the excess TDEAHfrom the chamber.

Next, the purge gas pulse is terminated, and a reactive gas comprisingozone or other reactive oxygen species from a remote plasma chamber ispulsed into the chamber with a carrier gas. For reactive oxygen, thecarrier gas is preferably argon or helium, either of which assists inmaintaining a stable oxygen plasma. It takes a reactive gas/carrierpulse of less than about 12 seconds to react with the TDEAH to formhafnium oxide or hafnium nitride, but again, the pulse need only be longenough so that substantially a monolayer of reactive oxygen isdeposited. After the reactive oxygen gas/carrier pulse, another pulse ofpurge gas is introduced into the chamber, and, as before, the time ofthe pulse of the purge gas need only be long enough to clear theunreacted reactive oxygen from the chamber. The pulse of theTDEAH/carrier, the pulse of the first purge gas, the pulse of thereactive oxygen gas/carrier, and the pulse of the second purge gascompletes one sequential deposition cycle. The deposition cycles arerepeated until a desired thickness of the hafnium oxide or hafniumnitride has been deposited. The time per cycle will vary depending onsubstrate or chamber size and other hardware parameters, on chamberconditions such as temperature and pressure and on the selection ofprecursor and reactive gas.

FIG. 3 is a schematic cross-sectional view of one embodiment of aprocessing chamber 200 which can be used to form films according toembodiments described herein. The chamber 200 includes a chamber body202 and a movable substrate support 212 disposed in the chamber tosupport a substrate 210. The substrate support 212 may include a vacuumchuck, an electrostatic chuck, or a clamp ring for securing thesubstrate 210 to the substrate support 212 during processing. Thesubstrate support 212 may be heated using an embedded heating element,such as a resistive heater, or may be heated using radiant heat, such asheating lamps disposed above the substrate support 212. A purge ring 222may be disposed on the substrate support 212 to define a purge channel224 which provides a purge gas to a peripheral portion of the substrate210 to prevent deposition thereon.

The chamber 200 includes a vacuum system 278 in communication with apumping channel 279 to evacuate any desired gases from the chamber 200and to help maintain a desired pressure or a desired pressure rangeinside a pumping zone 266 of the chamber 200.

A gas delivery apparatus 230 is disposed at an upper portion of thechamber body 202 to introduce the metal precursors, the reactive gasesand the purge gases into the chamber 200. The gas delivery apparatus 230comprises a chamber lid 232 which includes an expanding channel 234 anda bottom surface 260. The bottom surface 260 is sized and shaped tosubstantially cover a substrate 210 disposed on the substrate support212. The expanding channel 234 has gas inlets 236A, 236B to provide gasflows from two similar valves 242A, 242B via valve seat assemblies 244A,244B and delivery lines 243A, 243B. The gas flows from the valves 242A,242B may be provided together and/or separately. The valves 242A, 242Bmay be pneumatically actuated or may be electrically actuated.Programmable logic controller 248A, 248B may be coupled to the valves242A, 242B to control actuation of the valves 242A, 242B. Anelectrically actuated valve typically requires the use of a drivercoupled between the valve and the programmable logic controller. Thevalves 242A, 242B may be zero dead volume valves to enable rapidflushing of a reactant gas from the delivery lines of the valve 242A,242B.

Valves 242A and 242B are each coupled to separate precursors. Each iscoupled to a purge gas source, preferably the same purge gas source. Forexample, valve 242A is coupled to precursor gas source 238 and valve242B is coupled to reactant gas source 239, and both valves 242A, 242Bare coupled to purge gas source 240. Each valve 242A, 242B may beadapted to provide a combined gas flow and/or separate gas flows of theprecursor gas source 238 or reactant gas source 239 and the purge gassource 240. The reactant gas source 239 includes remote plasmageneration such as a microwave chamber to generate reactive gas specieswhen desired.

In reference to valve 242A, one example of a combined gas flow of theprecursor gas source 238 and the purge gas source 240 provided by valve242A comprises a continuous flow of a purge gas from the purge gassource 240 and pulses of a reactant gas from the precursor gas source238. In reference to valve 242A, one example of separate gas flows ofthe reactant gas source 238 and the purge gas 240 provided by valve 242Acomprises pulses of a purge gas from the purge gas source 240 and pulsesof a reactant gas from the reactant gas source 238.

The delivery lines of the valves 242A, 242B may be coupled to the gasinlets 236A, 236B through gas conduits 250A, 250B. Each gas conduit250A, 250B and gas inlet 236A, 236B may be positioned in anyrelationship to the expanding channel 234. Each gas conduit 250A, 250Band gas inlet 236A, 236B are preferably positioned normal (in which +β,−β=to 90°) to the longitudinal axis of the expanding channel 234 orpositioned at an angle +β or an angle −β (in which 0°<+β<90°; 0°<−β<90°)from a centerline of the gas conduit 250A, 250B to the longitudinal axisof the expanding channel 234. Therefore, the gas conduit 250A, 250B maybe positioned horizontally normal to the longitudinal axis of theexpanding channel 234, may be angled downwardly at an angle +β, or maybe angled upwardly at an angle −β to provide a gas flow towards thewalls of the expanding channel 234 rather than directly downward towardsthe substrate 210 which helps reduce the likelihood of blowing offreactants adsorbed on the surface of the substrate 210. In addition, thediameter of the gas conduits 250A, 250B may be increasing from thedelivery lines 243A, 243B of the valves 242A, 242B to the gas inlets236A, 236B to help reduce the velocity of the gas flow prior to itsentry into the expanding channel 234. For example, the gas conduits250A, 250B may comprise an inner diameter which is gradually increasingor may comprise a plurality of connected conduits having increasinginner diameters. The expanding channel 234 comprises a channel which hasan inner diameter which increases from an upper portion 237 to a lowerportion 235 adjacent the bottom surface 260 of the chamber lid 232. Inone aspect, the diameter of the expanding channel 234 is graduallyincreasing from the upper portion 237 to the lower portion 235 of theexpanding channel 234 to allow less of an adiabatic expansion of a gasthrough the expanding channel 234 which helps to control the temperatureof the gas. In one embodiment, the gas inlets 236A, 236B are locatedadjacent the upper portion 237 of the expanding channel 234.

At least a portion of the bottom surface 260 of the chamber lid 232 fromthe expanding channel 234 may be downwardly slopping or funnel shaped tohelp provide an improved velocity profile of a gas flow from theexpanding channel 234 across the surface of the substrate 210 (i.e.,from the center of the substrate to the edge of the substrate). In oneaspect, the bottom surface 260 is downwardly sloping to help reduce thevariation in the velocity of the gases as it travels between the bottomsurface 260 of the chamber lid 232 and the substrate 210 to help provideuniform exposure of the surface of the substrate 210 to a precursor orreactant gas.

The chamber lid 232 may have a choke 262 at a peripheral portion of thechamber lid 232 adjacent the perimeter of the substrate 210. The choke262 may comprise any circumferential downwardly extending protrusion.The choke 262 helps provide a more uniform pressure distribution withinthe volume or a reaction zone 264 defined between the chamber lid 232and the substrate 210 by isolating the reaction zone 264 from thenon-uniform pressure distribution of the pumping zone 266.

In one aspect, since the reaction zone 264 is isolated from the pumpingzone 266, a minimal amount of gas adequately fills the reaction zone 264to ensure sufficient exposure of the substrate 210 to the gas. Inconventional chemical vapor deposition, a chamber is required to providea combined flow of reactants simultaneously and uniformly to the entiresurface of the substrate in order to ensure that the co-reaction of thereactants occur uniformly across the surface of the substrate. In anatomic layer deposition based cyclical processing system, reactants areintroduced sequentially into the chamber to provide adsorbtion ofalternating thin layers of the reactants onto the surface of thesubstrate. Instead, a flow of a reactant needs to be providedrepetitively in an amount that is sufficient to adsorb a thin layer ofthe reactant on the surface of the substrate. Since the reaction zone264 may comprise a smaller volume when compared to the inner volume of aconventional CVD chamber, a smaller amount of gas is required to fillthe reaction zone 264 for a particular process in an atomic layerdeposition sequence. Because of the smaller volume of the reaction zone264, less gas, whether a deposition gas or a purge gas, is necessary tobe flowed into the chamber 200. Therefore, the throughput of the chamber200 is greater and the waste may be minimized due to the smaller amountof gas used reducing the cost of operation.

The chamber lid 232, as shown, includes a cap portion 272 and a chamberplate portion 270 in which the cap portion 272 and the chamber plateportion 270 form the expanding channel 234. An additional plate may beoptionally disposed between the chamber lid portion 270 and the capportion 272. In other embodiments, the expanding channel 234 may be madeintegrally from a single piece of material.

The chamber lid 232 may include cooling elements and/or heating elementsdepending on the particular gas being delivered therethrough (notshown). Controlling the temperature of the chamber lid 232 may be usedto prevent gas decomposition, deposition, or condensation on the chamberlid 232. For example, water channels may be formed in the chamber lid232 to cool the chamber lid 232. In another example, heating elementsmay be embedded or may surround components of the chamber lid 232 toheat the chamber lid 232. In one embodiment, components of the chamberlid 232 may be individually heated or cooled. For example, referring toFIG. 3, the chamber lid 232 may comprise a chamber plate portion 270 anda cap portion 272 in which the chamber plate portion 270 and the capportion 272 form the expanding channel 234. The cap portion 272 may bemaintained at one temperature range and the chamber lid 232 may bemaintained at another temperature range. For example, the cap portion272 may be heated by being wrapped in heater tape or by using anotherheating device to prevent condensation of reactant gases and the chamberplate portion 270 may be maintained at ambient temperature. In anotherexample, the cap portion 272 may be heated and the chamber plate portion270 may be cooled with water channels formed therethrough to preventthermal decomposition of reactant gases on the chamber plate portion270.

The chamber lid 232 may be made of stainless steel, aluminum,nickel-plated aluminum, nickel, or other suitable materials. In oneembodiment, the cap portion 272 comprises stainless steel and thechamber plate portion 270 comprises aluminum. In one embodiment, theadditional plate comprises stainless steel.

A control unit 280 may be coupled to the chamber 200 for controllingprocess conditions. For example, the control unit 280, may be configuredto control flow of various process gases and purge gases from gassources 238, 239, 240 through the valves 242A, 242B during differentstages of a substrate process sequence. The control unit 280 may becoupled to another controller that is located adjacent individualchamber components, such as the programmable logic controllers 248A,248B of the valves 242A, 242B. Bi-directional communications between thecontrol unit 280 and various other components of the chamber 200 arehandled through numerous signal cables collectively referred to assignal buses 288, some of which are illustrated in FIG. 3. In additionto control of process gases and purge gases from gas sources 238, 239,240 and from the programmable logic controllers 248A, 248B of the valves242A, 242B, the control unit 280 may be configured to be responsible forautomated control of other activities used in wafer processing, such aswafer transport, temperature control, chamber evacuation, among otheractivities, some of which are described elsewhere herein.

In operation, a first gas flow may be injected into the expandingchannel 234 of the chamber 200 by valve 242A together or separately(i.e., pulses) with a second gas flow injected into the chamber 200 byvalve 242B. The first gas flow may comprise a continuous flow of a purgegas from purge gas source 240 and pulses of a precursor gas fromprecursor gas source 238 or may comprise pulses of a reactant gas fromreactant gas source 239 and pulses of a purge gas from purge gas source240. The flows of gas travel through the expanding channel 234 as avortex flow pattern which provides a sweeping action across the innersurface of the expanding channel 234. The vortex flow pattern dissipatesto a downwardly flow toward the surface of the substrate 210. Thevelocity of the gas flow reduces as it travels through the expandingchannel 234. The gas flow then travels across the surface of thesubstrate 210 and across the bottom surface 260 of the chamber lid 232.The bottom surface 260 of the chamber lid 232, which is downwardlysloping, helps reduce the variation of the velocity of the gas flowacross the surface of the substrate 210. The gas flow then travels bythe choke 262 and into the pumping zone 266 of the chamber 200. Excessgas and by-products flow into the pumping channel 279 and are exhaustedfrom the chamber 200 by a vacuum system 278. In one aspect, the gasflows proceed through the expanding channel 234 and between the surfaceof the substrate 210 and the bottom surface 260 of the chamber lid 232proceeds in a laminar manner which aids in an efficient exposure of areactant gas to the surface of the substrate 210 and efficient purgingof inner surfaces of the chamber lid 232.

EXAMPLES

Hafnium oxide films were deposited at a chamber pressure of 4 Torr bypulsing TDEAH in a nitrogen carrier for 10 seconds. The chamber was thenpurged with a pulse of a nitrogen gas for 10 seconds. Next, reactiveoxygen and an argon carrier (Ar/O* ratio=1:2) was pulsed to the chamberfor 10 seconds. Once the reactive gas/carrier pulse was terminated, asecond pulse of nitrogen gas was introduced into the chamber for tenseconds to complete the cycle. This process was repeated for 40 cycleswith substrate temperatures ranging from 150° C. to 325° C. Theresulting hafnium oxide films were tested for WIW ThicknessNon-uniformity and the results are shown in FIG. 4. The results in FIG.4 show that atomic layer deposition (ALD) occurred at substratetemperatures between 150° C. and about 225° C. while pulsed CVD occurredabove 225° C. The ALD films showed excellent uniformity.

Hafnium oxide films were then deposited at a chamber pressure of 4 Torrand a substrate temperature of 175° C. by pulsing TDEAH and a nitrogencarrier from 2 seconds to 14 seconds. After the TDEAH pulse, a nitrogengas purge was pulsed into the chamber. For each cycle the nitrogen purgeafter the TDEAH/carrier pulse was the same length as the TDEAH/carrierpulse. Next, the nitrogen purge was terminated and a plasma of an argoncarrier and oxygen (Ar/O* ratio=1:2) was pulsed to the chamber for 2seconds to 14 seconds, matching the length of the TDEAH/carrier pulse.The cycle was then completed by a second nitrogen purge matching thelength of the TDEAH/carrier pulse. The cycle was repeated 40 times andthe resulting hafnium oxide films were measured for thickness, inaddition to WIW Thickness Non-uniformity. The results are shown in FIG.5 and show that pulse times from 10 to 14 seconds provide significantimprovement in uniformity.

FIG. 6 shows an Auger analysis of atomic concentrations of a hafniumoxide film deposited at a substrate temperature of 175° C. Although notcalibrated, the analysis shows that the film contained about 60 atomicpercent of oxygen and about 40 atomic percent of hafnium, and did notcontain detectable amounts of carbon. The atomic concentration of ahafnium oxide film prepared from the same precursor using a MOCVDprocess is shown in FIG. 7. The results in FIG. 7 show that thecomparison film retained a measurable amount of carbon.

The hafnium oxide films of the invention have utility in conventionaldevices such as replacing the hafnium oxide films, forming hafnium oxidefilms, and forming mixed metal films containing hafnium oxide asdescribed in the commonly assigned U.S. Pat. No. 6,858,547, filed Sep.27, 2002.

While the invention has been described herein with reference to specificembodiments, features and aspects, it will be recognized that theinvention is not thus limited, but rather extends in utility to othermodifications, variations, applications, and embodiments, andaccordingly all such other modifications, variations, applications, andembodiments are to be regarded as being within the spirit and scope ofthe invention.

1. A method for forming a hafnium material on a substrate, comprising:positioning a substrate within a process chamber; exposing the substrateto a hafnium precursor comprising the chemical formula (R′RN)₄Hf,wherein each R and R′ is independently a hydrogen group or an alkylgroup having from one to four carbon atoms; exposing the substrate toactive oxygen species formed by a remote plasma source; and exposing thesubstrate to active nitrogen species.
 2. The method of claim 1, whereinthe process chamber is pressurized at a pressure of less than about 10Torr and the substrate is heated to a temperature within a range fromabout 150° C. to about 225° C.
 3. The method of claim 1, wherein a purgegas is pulsed into the process chamber after exposing the substrate tothe hafnium precursor and after exposing the substrate to the activeoxygen species.
 4. The method of claim 1, wherein R or R′ is an ethylgroup.
 5. The method of claim 4, wherein the hafnium precursor is TDEAH.6. The method of claim 1, wherein the active oxygen species comprises amixture of argon and oxygen radicals.
 7. The method of claim 6, whereinthe mixture of argon and oxygen radicals has an argon:oxygen ratio of1:2.
 8. A method for forming a hafnium material on a substrate,comprising: positioning a substrate within a process chamber; exposingthe substrate sequentially to a hafnium precursor and active oxygenspecies, wherein the hafnium precursor comprises the chemical formula(R′RN)₄Hf, each R and R′ is independently a hydrogen group or an alkylgroup having from one to four carbon atoms, and the active oxygenspecies comprises ozone or other oxygen radicals; and exposing thesubstrate to active nitrogen species.
 9. The method of claim 8, whereinthe process chamber is pressurized at a pressure of less than about 10Torr and the substrate is heated to a temperature within a range fromabout 150° C. to about 225° C.
 10. The method of claim 8, wherein R orR′ is an ethyl group.
 11. The method of claim 10, wherein the hafniumprecursor is TDEAH.
 12. The method of claim 8, wherein the active oxygenspecies comprises a mixture of argon and oxygen radicals.
 13. The methodof claim 12, wherein the mixture of argon and oxygen radicals has anargon:oxygen ratio of 1:2.
 14. A method for forming a hafnium materialon a substrate, comprising: positioning a substrate within a processchamber; exposing the substrate to a process gas comprising a hafniumorganic precursor to form a layer of the hafnium organic precursor;purging the process chamber with a purge gas; exposing the substrate toactive oxygen species to form an oxide layer thereon; purging theprocess chamber with the purge gas; exposing the substrate to thehafnium organic compound to form another layer of the hafnium organicprecursor; purging the process chamber with the purge gas; exposing thesubstrate to active nitrogen species generated by a remote plasma sourceto form a nitride layer thereon; and purging the process chamber withthe purge gas.
 15. The method of claim 14, wherein the hafnium organicprecursor comprises the chemical formula (R′RN)₄Hf and each R and R′ isindependently a hydrogen group or an alkyl group having from one to fourcarbon atoms.
 16. The method of claim 15, wherein R or R′ is an ethylgroup.
 17. The method of claim 16, wherein the hafnium organic precursoris TDEAH.
 18. The method of claim 14, wherein the active oxygen speciescomprises a mixture of argon and oxygen radicals.
 19. The method ofclaim 18, wherein the mixture of argon and oxygen radicals has anargon:oxygen ratio of 1:2.
 20. The method of claim 14, wherein theprocess chamber is pressurized at a pressure of less than about 10 Torrand the substrate is heated to a temperature within a range from about150° C. to about 225° C.